This needs more thinking about. It is possible for instance to have invoices that contain both goods received and general ledger codes within the same invoice. So should we then just clone the GL parts?
A few years ago a customer asked for a default GL code by supplier. So for instance if you went to create an invoice for your electricity supplier it defaulted to the electricity GL account and all you had to do was fill in the date reference and the amount. Would thiss give you what you want?
I noticed when I did these changes that Phil has two virtually identical input forms in Suppliers.php one for a new supplier and one for editing an existing supplier. This is confusing as any change to the form such as this one has to be coded twice. It is also inconsistent with the way the rest of webERP works. They should really be amalgamated.
Also years ago someone requested on this forum for a default shipper by supplier. It got rejected at the time for reasons I didn't understand so I implemented it in my code. It is near identical change to the default GL code one so I could easily add it if you want.